Hijacking system("/bin/sh") to run arbitrary commands

Question

I'm trying to perform a privilege escalation attack using a binary which performs the call:

system("/bin/sh");

Is there a way to pass commands as "arguments" or such with the opened shell? (I don't see it opening, I guess it runs and dies as soon as it has nothing to do which is immediately).

Edit: I Cannot edit the code. It's compiled already.

Solution

If you execute

system("/bin/bash");

the shell enters into interactive mode. It reads commands from standard input and writes answers to standard output. The standard input and output is inherited from the calling (your) program. Your program will wait until the shell finishes (i.e. until you enter the command exit or you type ^D at the beginning of line). The shell will run with the same privileges as the calling program.

Comments

[Charles Duffy]

If the OP had an interactive TTY (and it were passed through on stdin), then the shell wouldn't be "immediately" exiting as they describe.